This invention relates to methods and apparatus for cooling hot bulk material, such as glowing coke, clinker or sinter material and, more particularly, to such methods and apparatus for cooling hot bulk material which utilize a cooling gas fed into a cooling tank at at least two feeding points arranged over each other, i.e., in the direction of flow of the bulk material, whereby the cooling gas flows upwardly in the tank around the bulk material as the latter flows downwardly to cool the same.
Methods and apparatus are known for cooling hot bulk material in a cooling tank through the use of a cooling gas which is introduced into the bulk material at several points by a gas distributor. In such known methods and apparatus, the cooling gas is collected after it has been heated whereupon it is fed to a heat recovery plant.
Conventional arrangements of the type described above the not entirely satisfactory in that the bulk material is not cooled to a sufficient extent, i.e., still has a relatively high temperature after the cooling operation. This of course is disadvantageous since the conveyer apparatus which transports the bulk material after the cooling operation can be damaged by the relatively high temperatures thereof. Of course, recovery of the heat of the hot bulk material is quite inefficient.
In order to overcome the disadvantages discussed above, it has been suggested to utilize special cooling devices which reduce the temperature of the cooling gas to even lower levels. However, this is not entirely satisfactory in that such special devices are expensive in both cost and operation.